Python - 计算 Pandas DataFrame 列值的数量
要计算列值的数量,请使用 count() 方法。首先,导入所需的 Pandas 库 −
import pandas as pd
使用两列创建 DataFrame −
dataFrame1 = pd.DataFrame( { "Car": ['BMW', 'Lexus', 'Audi', 'Tesla', 'Bentley', 'Jaguar'], "Units": [100, 150, 110, 80, 110, 90] } )
使用 count() 函数查找“Units”列值的数量 −
print"Count of values of Units column from DataFrame1 = ",dataFrame1['Units'].count()
通过同样的方式,我们计算了第 2 个 DataFrame 的数量。
示例
以下是完整代码 −
import pandas as pd # Create DataFrame1 dataFrame1 = pd.DataFrame( { "Car": ['BMW', 'Lexus', 'Audi', 'Tesla', 'Bentley', 'Jaguar'], "Units": [100, 150, 110, 80, 110, 90] } ) print"DataFrame1 ...\n",dataFrame1 # Finding count of values of a specific column print"Count of values of Units column from DataFrame1 = ",dataFrame1['Units'].count() # Create DataFrame2 dataFrame2 = pd.DataFrame( { "Product": ['TV', 'PenDrive', 'HeadPhone', 'EarPhone', 'HDD'], "Price": [8000, 500, 3000, 1500, 3000] } ) print"\nDataFrame2 ...\n",dataFrame2 # Finding count of values of all the column print"\nCount of column values from DataFrame2 = \n",dataFrame2.count()
输出
这将产生以下输出 −
DataFrame1 ... Car Units 0 BMW 100 1 Lexus 150 2 Audi 110 3 Tesla 80 4 Bentley 110 5 Jaguar 90 Count of values of Units column from DataFrame1 = 6 DataFrame2 ... Price Product 0 8000 TV 1 500 PenDrive 2 3000 HeadPhone 3 1500 EarPhone 4 3000 HDD Count of column values from DataFrame2 = Price 5 Product 5 dtype: int64
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